Manufacture of filaments for incandescent lamps.



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CHARLES 1?. STEINMETZ, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A-CORPORATION- OF NEW YORK.

MANUFACTURE OF FILAMENTS FOR INCANDESCENT LAMPS.

No Drawing.

To all whom it mag concern:

Be it known that I, CHARLES P. STEIN- nrerz, a citizen of the United States, residing at Schenectady, in the county of Schenectady and State of New York, have invented certain new and useful Improvements in the Manufacture of Filaments for Incandescent Lamps, of which the following is a specification.

My present invention comprises a novel method for use in the manufacture of filaments for incandescent lamps,'whereby the life and the efiiciency of such filaments may be increased.

To accomplish the result sought I cause chemical reaction or reactions to take place such as will drive off any traces of hydrogen, hydrocarbons, silica or the like from the body of the filament. For this purpose I prefer to use fluorin. Since, however, this gas is too reactive to permit it to be conveniently applied directly to the filaments I use it with a carrier, such as iodin, which carrier is of such character that it may be easily evaporated or volatilized and carriedofi when the filaments are heated during the exhaustion process. The compound which I have found effective is known as pentafiuorid of iodin (11%). By treating the ordinary carton filaments either flashed or Specification of Letters Patent. Application filed A rnao, 1904. Serial No. 205,653.

Patented Mar. 28, 1911.

proposed to use for the purpose mentioned a fluor-id of boron and also to use chlorin gas. The use of the first-menti0ned sub stance is objectionable for the reason-that a depositof boron is left in the filament,

while the use of thelatter substance is inefv fective because of its relative chemical inactivity.

What I do claim as'my invention and desire to secure by Letters Patent of the United States, is,

The method which consists in treating filaments for use in incandescent lamps with penta-fluorid of iodin. I

In witness whereof, I have hereunto set my hand this 29th day of April, 1904.

CHARLES P. STEINldETZ. Witnesses: l

BENJAMIN BVHULL, HELEN Onronn.

Copies of this patent may be obtained for five cents each, by addressing the Commissionerot Patents,

Washington, D. G. 

